High-pressure fuel pumps are used in fuel injection systems in order to compress, and thus apply high pressure to, fuel. The fuel under high pressure is then injected, by means of a fuel injection device, into combustion chambers of an internal combustion engine. In the case of gasoline internal combustion engines, the pressure lies in a range from 150 bar to 400 bar, and in the case of diesel internal combustion engines, the pressure lies in a range from 1500 bar to 3000 bar. The more the fuel is compressed, the lower the emissions produced during the combustion process. This may provide emissions reduction which is increasingly sought-after and required by law.
These high-pressure fuel pumps usually comprise piston pumps, the fuel being compressed by a pump piston in a pressure chamber by means of a translational movement of the pump piston. The non-uniform delivery of such piston pumps may, on a low-pressure side of the high-pressure fuel pump, produce fluctuations in the volume flow, which are associated with pressure fluctuations in the system as a whole. Also, for example, actively controlled inlet valves cause pressure pulsations on the low-pressure side of the high-pressure fuel pump during operation. As a consequence of these fluctuations or pressure pulsations, the high-pressure fuel pump can experience filling losses, so that correct metering of the quantity of fuel required in the internal combustion engine cannot be ensured. In addition, these pressure pulsations induce oscillations in components of the high-pressure fuel pump, which can cause undesirable noise or even damage to the individual components.
Therefore, in order to damp these pressure pulsations, low-pressure dampers are used on the low-pressure side, these dampers operating as hydraulic accumulators which smooth the fluctuations in the volume flow and thus reduce the resulting pressure pulsations. To that end, these low-pressure dampers usually have deformable elements. Now, if the pressure at the low-pressure side rises, these elements deform, thus making space for the excess fuel in the volume flow. When the pressure subsequently drops, the deformable element returns to its original shape and the stored fuel is thus released again. For example, low-pressure dampers are known which are installed on a head region of the high-pressure fuel pump. In addition to the greatest possible volumetric capacity, however, a further demand on a low-pressure damper is that it takes up the least possible structural space. Furthermore, it should be as inexpensive as possible and exhibit little complexity in terms of production.